Miscarriage
Loss of a pregnancy before 24 weeks, usually because a chromosomally abnormal conceptus stops developing and the uterus then separates and expels it: the clinical subtype simply reflects how far that expulsion has progressed.
In a nutshell
Most miscarriage begins with a chromosomally abnormal conceptus that stops developing; the named subtypes (threatened, inevitable, incomplete, complete, missed) simply describe how far the uterus has progressed in separating and expelling that failed pregnancy, as shown on ultrasound.
Classic presentation
Vaginal bleeding with lower abdominal cramping in early pregnancy; the cervical os and scan findings determine which subtype it is.
Key points
- Threatened: bleeding, closed os, viable pregnancy. Inevitable: open os, bleeding will progress. Incomplete: tissue remains, os open. Complete: everything passed, os closed. Missed: non-viable on scan without symptoms.
- Transvaginal ultrasound is what actually defines the subtype, not the history alone.
- Anti-D is needed in Rhesus-negative women having surgical management, or with heavier bleeding/pain after 12 weeks.
- Expectant management is appropriate first-line for many women; medical (misoprostol) and surgical options escalate from there.
- Fever or offensive discharge with bleeding suggests septic miscarriage and needs urgent treatment.
- Ectopic pregnancy must always be considered and excluded before assuming bleeding and pain are due to miscarriage.
First-line investigation
Transvaginal ultrasound to confirm viability, location and whether products remain in the uterus.
First-line management
Offer expectant management first where appropriate; escalate to medical (misoprostol) or surgical evacuation for heavy bleeding, infection or patient choice, with anti-D where indicated.
Exam traps
- A closed cervical os with ongoing bleeding but a confirmed non-viable pregnancy on scan is a missed miscarriage, not threatened.
- Pain typically follows bleeding in miscarriage, the reverse pattern to classic ectopic pregnancy.
- Anti-D is not routinely required for all miscarriages managed expectantly or medically before 12 weeks unless bleeding is heavy or painful.
Educational content pending clinical review. Not medical advice.